using MyWarehouse.Application.Common.Dependencies.DataAccess;
using MyWarehouse.Application.Common.Exceptions;
using MyWarehouse.Domain.Products;

namespace MyWarehouse.Application.Products;

public record FlashSaleCommand : IRequest, IMessage
{
    public int Id { get; init; }
    public decimal PriceAmount { get; init; }
    public int DurationDays { get; set; } = 1;
}

public class FlashSaleCommandHandler : IRequestHandler<FlashSaleCommand>
{
    private readonly IUnitOfWork _unitOfWork;
    private readonly IMessageSession _messageSession;

    public FlashSaleCommandHandler(IUnitOfWork unitOfWork, IMessageSession messageSession)
    {
        _unitOfWork = unitOfWork;
        _messageSession = messageSession;
    }

    public async Task<Unit> Handle(FlashSaleCommand request, CancellationToken cancellationToken)
    {
        var product = await _unitOfWork.Products.GetByIdAsync(request.Id)
                      ?? throw new EntityNotFoundException(nameof(Product), request.Id);

        product.FlashSale(request.PriceAmount, TimeSpan.FromDays(request.DurationDays));
        
        await _unitOfWork.SaveChanges();

        foreach (var evnt in product.GetUncommittedEvents())
        {
            await _messageSession.Publish(evnt);
        }

        return Unit.Value;
    }
}